<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
</head>
<body>
    <div id="app">
        <p>{{name}}</p>
        <p v-once>{{name}}</p>
        <!-- 控制台输出  vm.name=1  改变的是上面的name -->
    </div>
    <script>
        let vm = new Vue({
            el:"#app",
            data:{
                name:"111"
            }
        })
    </script>
</body>
</html>